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Sökning: hsv:(TEKNIK OCH TEKNOLOGIER) hsv:(Naturresursteknik) > Licentiatavhandling

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1.
  • André, Hampus, 1989 (författare)
  • Resource and Environmental Impacts of Resource-Efficiency Measures Applied to Electronic Products
  • 2018
  • Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
    • Natural resources such as ecosystems, land, water and metals underpin the functioning of economies and human well-being, and are becoming increasingly scarce due to growth in population and affluence. Metals are increasingly demanded for their specific properties as modern technology develops. The dependence on metals is of growing concern due to the environmental impacts related, for example, to energy use and local impacts from mining, as well as the scarcity risks posed by socio-economic, geological and geopolitical constraints. Thus, there is a clear need to use metals and other natural resources more efficiently. The vision of a circular economy has been proposed as a way to do this, for example by improving durability, reusing, repairing and recycling. Such so-called resource-efficiency (RE) measures are commonly assumed to be environmentally beneficial, although the evidence is not plentiful. It is plausible that focusing on recirculating products and materials could shift burdens to other environmental impacts or life cycle stages. It has therefore been argued that a life cycle-based approach, such as in life cycle assessment (LCA), is useful to critically assess the environmental implications of RE measures. LCA aims to quantify the environmental impacts of products over their entire life cycles - from cradle to grave - assessing a wide range of impacts such as toxicity, climate change and metal resource use. For metal resource use, however, there are a number of perspectives as to what constitutes the actual environmental problem. These perspectives are represented in a variety of life cycle impact assessment methods (LCIA) which have previously been shown to give diverging results. Electronic products are emblematic of metal resource use challenges since they deploy a broad spectrum of scarce metals. This thesis aims to provide knowledge on the potential for RE measures to reduce the environmental impacts of electronic products, by addressing the following research questions: (1) What resource-efficiency measures result in reduced potential environmental impacts and resource use – for what types of products and under what conditions? (2) How does extended use of electronic products through design for increased technical lifetime, reuse and repair affect environmental impacts, particularly metal resource use? (3) How does the application of different LCIA methods for metal resource use influence interpretations of resource-efficiency measures applied to electronic products? This thesis builds on three appended papers which are all based on comparative assessments of resource efficiency, studied as resource use and environmental impacts per function delivered, using LCA and material flow analysis. The results indicate that extended use of electronic products through increasing technical lifetimes, reusing and repairing, is generally resource-efficient. Exceptions may occur, however, if extended use is insufficient to motivate impacts from producing more durable products or spare parts. Use extension of electronic products leads to resource efficiency in two distinct ways: through the intended use extension and by increasingly steering material flows into recycling. Further resource efficiency could be realised by combining RE measures over the entire life cycles of products. With regards to metal resource use, the choice of LCIA method can influence the interpretation of the results of RE measures for electronic products. Therefore, it is advisable to use several complementary LCIA methods to minimise the risks of overlooking potentially important resources issues. Furthermore, better understanding and transparency of such issues is valuable in order to provide more comprehensive information to decision-makers.
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2.
  • Santén, Vendela, 1978 (författare)
  • Exploring logistics actions enabling environmentally sustainable freight transport
  • 2013
  • Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
    • To curb unsustainable freight transport trends; such as transport growth, larger dependency on road transport and generally an increased share of greenhouse gas emissions from the sector, actions needs to be taken among actors in the logistics system. The purpose of this thesis is to explore logistics actions that enable environmentally sustainable freight transport. This explorative research, based primarily on empirical data from interviews, focus groups, and a case study, adopts the perspectives of different actors in the logistics system: transport buyers, freight forwarders, transport operators, and authorities. The thesis identifies a wide range of actions in the logistics system to potentially enable environmentally sustainable freight transport. The perception from actors regarding what actions are important to adopt indicate that more knowledge among actors regarding how transport and traffic work can be reduced and how different actions affect each other are needed; especially how transport buyers acting affect the transport operations performed by freight forwarders and transport operators. By exploring what hinders environmentally sustainable freight transport in the interface between transport buyers and providers, it can be concluded that closer co-operation can provide better internal conditions for actors and new business solutions. Open dialogue, information sharing, and proactivity among both transport buyers and transport providers are essential. Furthermore, in order to increase load factor in practice, actions can be taken by transport buyers in the area of packaging, loading, and booking efficiency. More flexible time requirements will potentially increase the load factor. Gaining positive environmental effects from these changes is dependent on the freight forwarder’s actions in terms of consolidating with other transport buyers’ goods, route planning, and the positioning of vehicles. Since improvements in one actor’s system may not necessarily yield positive effects at a higher system level, it is important to also have a holistic view when aiming for environmentally sustainable freight transport. This thesis contributes with knowledge about how logistics actors can work toward environmentally sustainable freight transportation by providing insight for managers of transport buying and transport providing companies by exemplifying the interactions between actors and actions and their potential effects.
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3.
  • Böckin, Daniel, 1989 (författare)
  • Learning from assessments of resource efficiency measures and their impact on resource use and the environment - Based on a case of additive manufacturing and a review of assessment studies
  • 2018
  • Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
    • Resource efficiency measures have the potential to reduce the environmental and resource impacts of the current linear economy by decreasing the physical flows of material and energy associated with producing and using products and services. In order to investigate this potential, there is a need for assessments from a systems perspective, which for example enables the identification of possible trade-offs between different measures and aspects of resource efficiency depending on the product characteristics. The research was carried out in two parts, firstly by synthesising the learnings from a large number of assessment studies. The analysis was built on typologies formulated for mapping resource efficiency measures and product characteristics to the environmental and resource outcomes of the measures in each case. This resulted in a number of findings detailing under which conditions that resource efficiency measures yield environmental and resource benefits, as well as when there are possible trade-offs and limitations. Furthermore, some product characteristics were identified that are key in determining when resource efficiency measures are effective, namely whether products are durable, consumable, complex or whether they have significant impacts from extraction and material production or from their use. Products with significant impacts from the use-phase are called active products and give rise to trade-offs that are discussed in detail, specifically regarding under which conditions there are environmental and resource benefits from extended use or from reducing use-phase impacts. The second part of the research was a life cycle assessment of one such active product, namely 3D-printed truck engines. The aim was to investigate the resource efficiency potential of this emerging technology. Results showed that 3D-printing could lead to net improvements in life cycle impacts, by allowing redesigns of components for lower weight and thus lower fuel consumption. However, the conclusions were only valid under certain conditions, such ascareful material choice and a low-fossil electricity mix for the printing process, without which 3D-printing resulted in environmental deterioration compared to conventional manufacturing. Some results could be generalised to other applications and industries, for example the importance of a low-fossil electricity mix for 3D-printing, which is valid for any application of 3D-printing. In conclusion, useful knowledge on resource efficiency measures was produced both by synthesising many assessment studies and carrying out a single assessment study, especially on the topics of active products and additive manufacturing.
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4.
  • Chordia, Mudit, 1985 (författare)
  • Taking stock of large-scale lithium-ion battery production using life cycle assessment
  • 2022
  • Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
    • Battery electric vehicles are being increasingly favored as an alternative to internal combustion engine vehicles (ICEVs). This is mainly due to their lower environmental impact when compared to ICEVs over the vehicle’s lifetime. Life cycle assessment (LCA) studies focusing specifically on battery electric vehicles (BEVs) have identified battery cell production as an environmental hotspot in the BEV’s life cycle. However, lack of primary or industrial data, different technical scopes, and varying data quality, limit a thorough understanding of the environmental impacts of cell production. Further, with scaling-up of battery production (to meet the rising demand for BEVs), the source and level of impacts are expected to change. In response, the main aim of this thesis is to explore and understand the implications of upscaling in battery production. An example of such a change is provided at the mining sites where raw materials for lithium used in batteries are extracted and produced. As mining continues, over time, the ore grades at these sites decline. Thus, this thesis also aims to investigate the effect of declining ore grades on the overall impacts from cell production. A sub-goal is to understand the relevance of background data in LCA studies and its effect on overall results. The technical scope of this thesis is the production of a graphite-NMC:811 21700 type cylindrical cell. To assess the environmental impacts of upscaling, production in a small-scale facility is compared to production in a large-scale facility. Next, the impact of declining ore grades on overall cell production is estimated by analyzing the data from multiple mining sites for lithium, with varying ore grades and different types of sources – spodumene and brine. To assess the effect of background database on overall results, the LCA model for cell production was coupled with different versions of the Ecoinvent background database. Lastly, a physics-based model platform, developed in cross-disciplinary collaboration, is proposed with the objective of filling data gaps in LCA of lithium-ion batteries (LIBs). The model platform will help link the cell design aspects such as power or energy optimization to changes in the individual cell production processes. Further, the model platform will help expand the technical scope to broadened set of cell geometries and chemistries, and increase the precision in use phase modeling as well. The results show that the upscaling leads to a reduction in environmental impacts from cell production. This is due to higher energy and material efficiency of cell production at large scale. Further, when low-carbon intensive sources are used, then the impacts from cell production shift almost entirely to the raw material extraction and production phase. In the context of declining ore grades, the type of source and grade of lithium account for 5-15% of the global warming impacts from cell production. This implies that future environmental impacts from LIB production could increase, due to increased chemical and energy inputs, in response to declining ore grades at mining sites. The changes in the background data have a significant bearing on the overall results. These are due to evolving technical systems and an improved representation of these systems in terms of data quality and geo-spatial representativeness. Lastly, preliminary results from the physics-based model platform show that accounting for variations in cell design can further add variability in results.
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5.
  • Hermansson, Frida, 1988 (författare)
  • Assessing the future environmental impact of lignin-based and recycled carbon fibres in composites using life cycle assessment
  • 2020
  • Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
    • Carbon fibre reinforced polymers (CFRPs) are composite materials that are gaining attention for their lightweighting and strengthening properties in a wide range of applications. However, using them instead of conventional materials (such as steel or other composites) does not automatically lead to a decrease in life cycle climate impact or energy use. This is the result of the energy-intensive production of the carbon fibres. Two routes that could mitigate this problem are: 1) the use of lignin for carbon fibre production and 2) the use of recycled carbon fibres. This thesis assesses how these two routes could decrease the environmental impact of carbon fibres in composites, and how challenges connected to assessing these emerging technologies can be handled using life cycle assessment (LCA). The two routes were assessed by conducting a meta-analysis of earlier LCAs of CFRPs and lignin production and three different LCA case studies. Results show that both using lignin as a raw material and using recycled carbon fibres have good potential to decrease the environmental impact of CFRPs, making them more environmentally competitive than other materials. It was found that the transition from polyacrylonitrile (PAN) to lignin as a raw material has good potential to decrease the environmental impact of future carbon fibres. However, the extent of this potential depends on both internal factors, such as process development, and external factors, such as the development of the lignin market and the future energy supply system.
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6.
  • Kanchiralla, Fayas Malik, 1989 (författare)
  • Life cycle navigation through future energy carriers and propulsion options for the energy transition in shipping
  • 2023
  • Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
    • The shipping industry's heavy reliance on fossil fuels has a detrimental effect on the global climate, human health, and the natural environment. The shipping sector now relies on the use of cheap and energy-dense heavy fuel oil and is perceived as ‘difficult-to-decarbonize’. Presently the shipping sector is adopting incremental emission reduction measures related to operational and technological energy efficiency solutions. However, to meet the global climate target, the transition from fossil-based marine fuels to renewable energy carriers is needed. Electro-fuels, which are produced from low-carbon electricity, or direct use of electricity with battery storage, are two pathways for energy transition included in this thesis. This thesis aims to assess the possible influence of the above two decarbonization paths based on energy demand, environmental performance, and economic performance across the whole life cycle of ships. The assessment is performed for hydrogen, ammonia, methanol, and battery-electric on three case study vessels using prospective life cycle assessment (pLCA) and life cycle costing (LCC). The pLCA is based on systems thinking used for the environmental assessment of emerging technologies that are in an early stage of development, and the LCC is used for the economic assessment of technologies over the life cycle based on the same systems thinking. To understand the environmental and economic tradeoffs for decision making an integrated assessment of pLCA and LCC is employed in the thesis. Considering the complexity and challenges of integration, a framework termed ‘integrated life cycle framework’ is developed for this thesis, allowing for consistent assessment to understand tradeoffs. This framework can be useful for other transport sectors. The study shows that there is a substantial potential for reducing the environmental impact of shipping through the studied pathways; however, this depends on the carbon intensity of the electricity used in fuel production. Technically, not all fuels are suitable for all vessels. Their suitability is primarily determined by the amount of fuel required for bunkering and the amount of space available onboard. Reduced climate impact comes at the expense of several other impact categories, such as human toxicity, water use, and resource use (minerals and metals). For the same type of fuel, fuel cells have greater impact reduction potential than engine options; however, engines are more cost competitive. Fuel price and utilization rate also influence cost competitiveness. The total life cycle cost of all the studied options is significantly higher than the conventional diesel option, and the critical parameter is the cost of the fuel. The cost of fuel is sensitive to the price of electricity. The carbon abatement cost estimated in this study shows that policies should be designed to imply at least a cost of 250–300 €/tCO2eq for emitting greenhouse gases to make the assessed fuel options cost competitive.
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7.
  • Willskytt, Siri, 1989 (författare)
  • How can consumables be made more resource efficient? Environmental and resource assessment of measures
  • 2018
  • Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
    • The global population growth paired with increasing consumption per capita puts resource efficiency and sustainability on the political agenda. Consequently, the need for resource-efficient and sustainable products, including consumables, is expected to increase in the future. Strategies and measures for resource-efficient products are being developed, however, with less focus on consumables. This thesis aims to investigate how consumables can be made more resource efficient. The research was carried out in two parts. First, a life cycle assessment was carried out on a selected consumable, namely an incontinence product. The aim was to investigate the potential to improve the resource efficiency of incontinence products by assessing four different resource efficiency (RE) measures which could be applied within a short time frame using current technology. The measures included reduce losses in production, change material composition to a larger proportion of renewables, shift to a partly multiple-use product and improve the use of the product through customisation. The second part of this thesis focused on synthesising learnings from a number of assessment studies. The analysis was based on typologies formulated for mapping resource efficiency measures and product characteristics. This resulted in a number of findings detailing under which circumstances resource efficiency measures yield environmental and resource benefits, as well as when there are possible trade-offs. The assessment studies of consumables were selected for a more detailed analysis in this thesis. Based on the review of cases and the typology of RE measures, the following RE measures were found applicable to consumables: reduce losses in production, reduce material use in products, change material in product, use effectively, shift to multiple-use products, reduce use of auxiliary materials and energy, recycle, digest anaerobically or compost, recover energy, and landfill. These are more measures which could potentially be applied to consumables than commonly discussed in the circular economy literature. Moreover, the identified measures among the cases all showed potential to improve resource efficiency. For the measure shift to multiple-use product, it was important for the product to last enough times to outweigh the environmental impact from production. In addition, an efficient maintenance system using electricity with low fossil content was an important element for achieving RE. When changing the material in a product, a risk of burden shifting between environmental impact categories was identified. Moreover, the measures applied to the incontinence products were found to be widely combinable, which could ultimately lead to greater resource efficiency. Others findings were that some measures are interdependent and that many, if not most, are dependent on design.
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8.
  • Andersen, Martin, 1985 (författare)
  • Solar district heating for low energy residential areas
  • 2019
  • Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
    • The integration of a solar thermal system into a district heating network can be a cost-effective solution, especially for new low-energy residential areas. Because of this, many new small solar district heating systems are built at the same time as the buildings, allowing for a more holistic approach to the design and construction. In doing so, it is possible to optimise the integration of the solar thermal system with respect to both cost and technical layout. This thesis presents studies that aim to investigate the most energy efficient distribution concept for successful implementation of solar district heating technology. An existing solar assisted district heating system is modelled in simulation software and the distribution system is varied in order to find out whether there is a more energy efficient option. Three system concepts are investigated: 1.      A Hybrid system using a combination of high-temperature, conventional steel pipe primary culvert, intermediate substations containing solar buffer stores and a low-temperature, EPSPEX secondary culvert with DHW-circulation (so-called GRUDIS). 2.      A Conventional distribution system with steel pipes, higher operating temperatures and centralized solar buffer stores. 3.      An All GRUDIS system, using only EPSPEX distribution with DHW-circulation, lower operating temperatures and centralized solar buffer stores. A sensitivity analysis is performed by simulating the three different distribution system for various linear heat densities, with the added objective of detecting any range-bound limitations of the different distribution systems. Results indicate that both the hybrid and All GRUDIS distribution concept is preferable to conventional DH distribution regardless of the network heat density. The hybrid concept seems preferable in denser district heating networks, but results are inconclusive regarding the best concept for sparser networks. Preliminary economic considerations show that the initial investment costs may be reduced by changing from a Hybrid to an All GRUDIS distribution concept, although a more detailed analysis is needed to draw conclusions about the most economical solution. Keywords: District heating, solar thermal, simulation, renewable energy, 4DH.
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9.
  • Anderson, Robert, 1988 (författare)
  • Investigating the Relation between Efficient, Effective and Sustainable Remediation of Contaminated Sites
  • 2018
  • Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
    • Remediation of contaminated sites reduces negative impacts to humans and the environment, but the process itself is typically associated with high costs to society and large environmental footprints. The sustainable remediation concept has, over the past decade, brought increased attention to the often-overlooked contradictory effects of site remediation. At the same time, the Swedish Environmental Protection Agency (SEPA) is concerned over the slow progress of publicly funded projects, calling for more efficient and effective remediation. The aim of this thesis is to investigate the impact of a sustainability view on the efficiency and effectiveness of contaminated site remediation. How efficiency and effectiveness are considered in literature with respect to contaminated sites was studied. The contribution of a sustainability view on the selection of remedial actions was demonstrated through scenario analysis (Paper I). This involved using the SCORE sustainability assessment method to analyze four real case study sites in Sweden. Remediation alternatives at the same four case studies were assessed based on project efficiency and effectiveness indicators found from literature and group interviews (Paper II). Sustainability assessment, considering broader environmental effects, soft social aspects, and economic externalities, can result in a decision support outcome which differs compared with more limited assessment approaches, typically balancing trade-offs such as the extent of remediation with negative secondary effects such as emissions. The studied effectiveness and efficiency indicators, pertaining primarily to time, costs, and amounts removed, generally favour the most extensive and low-cost alternatives, respectively. The indicators are not seen to strongly support the most sustainable alternatives, however a full sustainability view likely leads to less extensive and expensive remediation projects compared to a traditional assessment approach.
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10.
  • Bannova, Olga, 1964 (författare)
  • Extreme environments - Design and human factors considerations
  • 2014
  • Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
    • The starting point of this research is based on my experience at SICSA performing research and design for extreme environments, including orbital and lunar planetary facilities, disaster shelters, polar stations and offshore surface and submersible habitats. This thesis explores what aspects and issues of design and planning processes in extreme environments have to be addressed in a similar way and therefore may be used as a basis for further work toward PhD thesis to develop a methodological planning tool or matrix. That "tool" will be proposed for the purpose of facilitating a dialogue between all parties involved during developments in extreme conditions of Polar Regions.This work investigates both sides of any activity's planning process for Polar Regions: physical conditions and human factors and as an important part of the latter – possible human error complications. The complexity of the problem calls for a multi-disciplinary approach where the many facets of sustainability have to be also addressed. Dealing with the difficulty of combining multiple components is a role for an architect as a facilitator for a dialogue between all actors involved in development activities in extreme environments.Although requirements and hardships specific to diverse extreme environments are outlined at the beginning of the text, the study is later more focused on polar and boreal sites and based on two case studies located there. The text is also based on an overview of related to research problem technical papers, discussions with professionals about their work experience with projects in extreme conditions, and students' workshops debating strategies to form sustainable behavior and design practices.This study finds that an interdisciplinary, comprehensive approach includes highlighting influences upon general habitat requirements, and constraints upon delivery, construction, and special provisions for safety and hazard intervention. Optimization of such design requirements based on a summary of design considerations will be a key element for future development of systematic planning approach.In summary, the next steps of the research advancement are outlined; emphasizing the importance of equal attention to all elements of the project development, including human factors and psychological aspects, in design and planning processes. Such an approach is essential to enable successful sustainable development and maintenance practices.
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